Salt (LiF) Regulated Fluorescence Switching

A supramolecular host-guest complex stimulated by lithium cation and fluoride anion, functioning as reliable fluorescence "Off-On-Off" switching system has been developed. Nonfluorescent, receptor-bound fluorophore is exclusively displaced by second guest, fluoride anion to release the fluorophore that becomes highly fluorescent in guest concentration dependent way. Again, this process is completely reversed upon exposure to Li + . The entire process is an excellent model for fluorescence-based logic system.